Mounting means for semiconductor devices



June 29, 1965 A. e. MUELLER MOUNTING MEANS FOR SEMICONDUCTOR DEVICESFiled Feb 13', 1963 INVENTOR. ARMAND G. MUELLER BY fig 720464.)

United States Patent 3,192,444 MOUNTING MEANS FOR SEMICONDUCTOR DEVICESArmand G. Mueller, Wauwatosa, Wis., assignor to Square D Company, ParkRidge, 111., a corporation of Michigan Filed Feb. 13, 1963, Ser. No.258,327 4 Claims. (Cl. 317 -100) This invention relates to a mountingstructure and heat sink for semiconductor devices, and more particularlyto a mounting structure and heat sink for transistors, siliconcontrolled rectifiers, semiconductor diodes, and the like,

which facilitates their use for industrial control purposes.

When semiconductor devices are used as components of controllers of anindustrial control system, it is desirable to mount the devices on thecontroller panels together with other components of the control system.This is often difficult to do because semiconductor devices as usuallymanufactured do not include mounting means suitable for mounting thedevices on the metal or insulating panels of such controllers andbecause semiconductor devices usually must be mounted inthermally-conducting relation to a heat sink. However, terminal stripscomprising separable terminal block units and specifically designed formounting on the panels of such controllers are available. The terminalstrips are used to facilitate the electrical connection of thecontroller to the source and the load, or to other controllers, and tofacilitate the making of electrical connections between the componentsof the controller. The individual terminal block units of a terminalstrip are usually aligned in a row and generally each comprises aninsulating block carrying a metal connector arranged for interconnectingtwo wires, but other insulating blocks in the row may be arranged tocarry fuse clips, manual disconnect switches, or the like, instead of ametal connector.

In accordance with this invention, there is provided a generally ilat,rectangular, metal plate adapted for holding one or more semiconductordevices in good heat conducting relation therewith and arranged to besecured to an insulating mounting block complementary .to the terminalblock units of a terminal strip thereby to permit the mounting block tobe aligned in a row with the terminal block units directly on acontroller panel or on a separate mounting structure which, in turn, ismounted on the panel. The plane of the plate is preferably transverse tothe longitudinal axis of the row of blocks, and the plate not onlyserves as a mounting means and a heat sink for the semiconductordevicesbut also as a convenient means for making electrical connections to thesemiconductor devices.

An object of the invention is to provide an improved mounting means forsemiconductor devices.

Another object is to provide an improved mounting means and heat sinkfor semiconductor devices.

Another object is to provide a mounting means and heat sink forsemiconductor devices that is complementary to separable terminal blockunits of a terminal strip for convenient alignment in a row therewith ona controller panel.

Another object is to provide an improved mounting structure forsemiconductor devices that facilitates the protection of the devices byfuses.

Other objects and advantages of the inventionwill become apparent fromthe following description, wherein reference ismade to the drawings, inwhich:

FIGURE 1 is a perspective view of a preferred form of the mountingstructure and heat sink of this invention assembled with a fuse blockunit and terminal block units of a terminal strip. I

FIGURES 2, 3, and 4 are a top plan, an end, and a side 3,192,444Patented June 29, I965" ICE view, respectively, of the mountingstructure of FIG- URE 1.

The invention is described herein as constructed to be used with theterminal strip described in Van Valkenburg and Nielsen Patent No.2,981,922, issued April 25, 1961, its adaptation for use with otherterminal strips being obvious. As shown in FIGURE 1 and as more fully described in the Van Va-lkenburg and Nielsen patent, a terrninal strip inaccordance with the patent comprises an elongated metal channel 10slidably carrying in a row by dove-tail connections a plurality ofterminal block units 11 and 12 loosely interlocked with each other bycomplementary tongues and slots to be described and gripped fromopposite ends between insulating end clamp units, such as the end clampunit .14, also having dove-tail connections with the channel 10 andfastened to the channel as by screws 15. A separate barrier or reversingblock unit 14a interposed between the end clamp unit 14 and the blockunit 12 is loosely interlocked with both the clamp unit 14 and the blockunit 12 and also has the dovetail connection with the channel 10. Thedove-tail connections are loose enough to permit the unit 11, 12, 14,and 14a to be removed from and replaced on the channel transverselythereof by tilting of the units with respect to the channel 16) when thescrews 15 are loosened and the units are moved slightly away from eachother along the channel. The channel It) may be fastened conveniently toany vertical or horizontal surface of a controller.

Each of the terminal block units 11 and 12 comprises a molded insulatingblock 16 having a base portion 17 with a wall portion 18 extendingupwardly therefrom at one end and a central projection. '19 extendingfrom the wall portion 18 and overlying in spaced relation an upper face20 of the base portion 17 to grip the central portion of an elongatedflat metal connector 21, in the case of the block unit 11, or thecentral portion of an elongated metal connector 22 with box-type endportions 23, in the case of the block unit 12. The connectors 21 and 22,respectively, have at opposite ends screw means .24 and 25 for securingwires thereby to complete an electrical connection from one side of therespective projections 19 to the other.

In addition to the terminal block units 11 and 12, the barrier blockuni-t 14a and the end clamp uni-t '14, the channel 10 is shown in FIGURE1 as carrying a fuse block unit 26 comprising a base portion 28 with anupstanding wall portion 29 at one end, and a pair of spaced fuse clips30 and 31 receiving ferrules, respectively, of a cartridge fuse 32. Thefuse clips 30 and 31 illustrated are of :the type described in thecopending patent application of Erik J. Nielsen, Serial No. 751,427,filed July 28, 195 8, now abandoned, and assigned to the assignee of thepresent application. As fully described in the Nielsen application, eachof the fuse clips 30 and 31 thus has openings 34 in its jaws,respectively, which restrain the fuse 32 in an upright, disconnectedposition when moved to that position by swinging one end portion of thefuse 32 upwardly about the other end portion as an axis. Terminalportions 35 of each of fuse clips 30 and31 receive wire-clamping screws36, respectively, the lower end portions of which extend freely intosuitable recesses 38, respectively, formed in the base portion 28.

As seen most clearly in FIGURES 2, 3, and 4, a semiconductor mountingstructure and heat sink unit 40 in accordance with this invention isarranged to be mounted on the channel 11) in the same manner as theother block units, and to this end comprises an insulating block 41having a body portion 42 with an upstanding wall 43 at one end. Theblock 41also has opposite end faces 44 and 45 and opposite side faces45. A bottom face of the block 41 has downwardly and inwardly slopingface Lad surfaces 49 on opposite sides of a downwardlycpening, generally"IT-shaped recess 51 complementary to the T- shaped channel it}; butsufficiently larger so that the block 41 can be moved easilylongitudinally along the channel and can be removed therefrom orreplaced thereon transversely by tilting with respect to the channel.The end face {M has a pair of spaced-apart horizontally aligned bossesor tongues 52 and the end face 45 has a pair of spaced-apart recesses orslots 55 complementary to the tongues 52. It will be understood that theblocks of the other units 1.1, 12, and as have similar tongues andslots, the barrier unit 14a has similar tongues on both end faces, andthe clamp unit 14 has similar slots, so that the units, when mounted onthe channel lift in any desired order, can be interlocked with the nextadjacent unit or units.

A top face of the block 41 has a pair of recesses 56 and '1 nearopposite side edges, respectively, each provided with anangularly-disposed longitudinal groove 53 in its outer Wall. Each of apair of recesses 59 and 6&3 formed in the top face on opposite sides ofa raised central portion 61 has a longitudinal groove as in its innerwall horizontally aligned with the entry portions of the grooves 53. Therecesses 5s and 59 define a barrier as therebetween and the recesses 57and 69 define a similar barrier 64 therebetween. An upper surface of theprojection 61 is provided with a recess 66 to receive an indicia strip.

The semiconductor mounting and heat sink unit 4%} also comprises a metalplate 68 preferably formed of alumihorn and of generally rectangularconfiguration having a pair of spaced lower flange portions 69 and 7tinterrupted by a notch 71 which has a widened portion '71:: extendinginto a main upstanding portion 72 of the plate. Outer end portions 74and 75 of the flange portions 69 and '70 extend beyond the side edgefaces of the portion 72 and are bent downwardly for slidable receptionin the grooves 53, respectively. The inner portions of the flanges 69and 70 extend inwardly from the respective side edges of the widenedslot portion 71a to permit slidable reception thereof in the grooves 62,respectively. The plate 68 is securely held in an upright position onthe block 41 by sliding it from the end face 45 toward the wall portion43 with the flange portions 69 and 70 received in the grooves 58 and 62as just described.

The flange portions as and 70 may receive wire clamping screws 76 and78, respectively, to facilitate the making of electrical connections tothe plate 68.

A plurality of flanged circular openings such as the openings 8d and 81are formed in the main portion 72 of the plate d8 as by drawing, forreception, as by a press fit, of the cylindrical metal housings ofrespective semi- ,rcaaaa conductor devices, such as a device 82 shownmounted in the opening 81. Cylindrical flanges 89a and 81a of therespective openings 80 and 81 serve to provide an extensive area ofcontact with the semiconductor devices to provide a good electricalconnection and to facilitate transfer of heat from the devices to theplate 68 which thus serves as a heat sink.

Although various modes of completing connections to terminals of thesemiconductor devices such as the device 82 are possible, the one shownin FIGURE 1 comprises a wire 84 connected to the terminal portion 35 ofthe fuse clip 35} from where the circuit is completed through the fuse32 to the terminal portion 35 of the fuse clip 31, a wire 85 to aterminal 82a of the semiconductor device 82, the plate 68, and a wire 86from the wire clamping screw 76 in the flange portion 69. The fact thata terminal block or a block provided with a knife switch may bepositioned adjacent the mounting block 41 on either side along the,channel 10 and that connection may be made by either of the screws 76,78, or both, facilitates the connection of the semiconductor into thecircuitry of the controller on which the channel It) is mounted.

Having thus described my invention, I claim:

1. A mounting structure for semiconductor devices comprising aninsulating mounting block having a base portion and a barrier portionextending perpendicular to the base portion, said base portion an endcomplementary in shape to an end on a base portion of other insulatingmounting blocks for assembly therewith in a row to form a strip ofblocks for mounting in assembled relation on a controller, a generallyflat metal plate secured to the base portion and extending outwardlytherefrom in a plane parallel to the barrier portion and transverse tothe longitudinal axis of a row of blocks which are assembled with themounting block to form said strip of blocks, said plate having means formounting a semiconductor device thereon in good electrical and heatconducting relation thereto, and means for making an electricalconnection to said plate.

2. A mounting structure for semiconductor devices comprising aninsulating mounting block having an end complementary in shape to an endof other insulating blocks and adapted to be assembled therewith in arow to form a strip of blocks, a generally flat metal plate, saidmounting block having a pair of angularly disposed and oppositelyextending grooves formed the-rein and said plate having flange portionsslidably received in said pair of grooves to secure said plate to saidmounting block, said plate extending outwardly from said mounting block,and having means for mounting a semiconductor device thereon in goodheat conducting relation thereto and means for connecting the device inan electric circuit.

3. A mounting structure for semiconductor devices comprising aninsulating mounting block having an end complementary in shapeto an endof other insulating blocks for being assembled therewith in a row toform a strip of blocks for mounting in assembled relation on a panel, agenerally flat metal plate, a plurality of grooves formed in said blockand extending perpendicular to the said end of the mounting block,flange portions on said plate received in said grooves, respectively, tosecure said plate to said mounting block with said plate extendingoutwardly therefrom in a plane parallel to said end of the mountingblock, said plate having a flanged opening therein for mounting asemiconductor device thereon in good electrical and heat conductingrelation thereto, and means for making electrical connections to saidplate.

4. A mounting structure for semiconductor devices comprising aninsulating block, a generally flat metal plate, a plurality of groovesformed in said block, flange portions on said plate received in saidgrooves, respectively, thereby to secure said plate to said block withsaid plate having a portion disposed perpendicular to the flangeportions extending outwardly therefrom beyond portions of the peripheryof the block, said plate having a flanged opening therein for mounting asemiconductor device in good electrical and heat conducting relationthereto, and a separate means for making electrical connections to saidplate.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCESSnap-on Terminal Blocks, Electrical Construction and Maintenance, July1961, page 120.

DARRELL L. CLAY, Primary Examiner. JOHN P. WILDMAN, E. JAMES SAX,Examiners.

1. A MOUNTING STRUCTURE FOR SEMICONDUCTOR DEVICES COMPRISING ANINSULATING MOUNTING BLOCK HAVING A BASE PORTION AND A BARRIER PORTIONEXTENDING PERPENDICULAR TO THE BASE PORTION, SAID BASE PORTION AND ENDCOMPLEMENTARY IN SHAPE TO AN END ON A BASE PORTION OF OTHER INSULATINGMOUNTING BLOCKS FOR ASSEMBLY THEREWITH IN A ROW TO FORM A STRIP OFBLOCKS FOR MOUNTING IN ASSEMBLED RELATION ON A CONTROLLER, A GENERALLYFLAT METAL PLATE SECURED TO THE BASE PORTION AND EXTENDING OUTWARDLYTHEREFROM IN A PLANE PARALLEL TO THE BARRIER PORTION AND TRANSVERSE TOTHE LONGITUDINAL AXIS OF A ROW OF BLOCKS WHICH ARE ASSEMBLED WITH THEMOUNTING BLOCK TO FORM SAID STRIP OF BLOCKS, SAID PLATE HAVING MEANS FORMOUNTING A SEMICONDUCTOR DEVICE THEREON IN GOOD ELECTRICAL AND HEATCONDUCTING RELATION THERETO, AND MEANS FOR MAKING AN ELECTRICALCONNECTION TO SAID PLATE.